▎ 摘　　要

We examine the mechanical properties of graphene devices stretched on flexible elastomer substrates. Using atomic force microscopy, electrical transport measurements, and mechanics simulations, we show that microrips form in the graphene during the initial application of tensile strain; however, subsequent applications of the same tensile strain elastically open and close the existing rips. Correspondingly, while the initial tensile strain degrades the devices' transport properties, subsequent strain-relaxation cycles affect transport only moderately, and in a largely reversible fashion. Graphene's electrical and mechanical robustness even after partial mechanical failure is unique among conducting thin films. This understanding of the creation and dynamics of rips in graphene is relevant to the design of flexible graphene-based devices which are required to function under strain.